“My barograph needle marked forty-one thousand three hundred when I became aware that I could go no farther.  Physically, the strain was not as yet greater than I could bear but my machine had reached its limit.  The attenuated air gave no firm support to the wings, and the least tilt developed into side-slip, while she seemed sluggish on her controls.  Possibly, had the engine been at its best, another thousand feet might have been within our capacity, but it was still misfiring, and two out of the ten cylinders appeared to be out of action.  If I had not already reached the zone for which I was searching then I should never see it upon this journey.  But was it not possible that I had attained it?  Soaring in circles like a monstrous hawk upon the forty-thousand-foot level I let the monoplane guide herself, and with my Mannheim glass I made a careful observation of my surroundings.  The heavens were perfectly clear; there was no indication of those dangers which I had imagined.

“I have said that I was soaring in circles.  It struck me suddenly that I would do well to take a wider sweep and open up a new airtract.  If the hunter entered an earth-jungle he would drive through it if he wished to find his game.  My reasoning had led me to believe that the air-jungle which I had imagined lay somewhere over Wiltshire.  This should be to the south and west of me.  I took my bearings from the sun, for the compass was hopeless and no trace of earth was to be seen—­nothing but the distant, silver cloud-plain.  However, I got my direction as best I might and kept her head straight to the mark.  I reckoned that my petrol supply would not last for more than another hour or so, but I could afford to use it to the last drop, since a single magnificent vol-plane could at any time take me to the earth.

“Suddenly I was aware of something new.  The air in front of me had lost its crystal clearness.  It was full of long, ragged wisps of something which I can only compare to very fine cigarette smoke.  It hung about in wreaths and coils, turning and twisting slowly in the sunlight.  As the monoplane shot through it, I was aware of a faint taste of oil upon my lips, and there was a greasy scum upon the woodwork of the machine.  Some infinitely fine organic matter appeared to be suspended in the atmosphere.  There was no life there.  It was inchoate and diffuse, extending for many square acres and then fringing off into the void.  No, it was not life.  But might it not be the remains of life?  Above all, might it not be the food of life, of monstrous life, even as the humble grease of the ocean is the food for the mighty whale?  The thought was in my mind when my eyes looked upwards and I saw the most wonderful vision that ever man has seen.  Can I hope to convey it to you even as I saw it myself last Thursday?